US officials necessarily has contact with Montesinos because of his position

US Embassy in Peru

The tape is the third "Vladivideo" to appear recently, apparently linking political groups with Mr Montesinos.

Political groups tainted by such videos have accused interim President Valentin Paniagua's government of manipulating the release of tapes to favour front-runner Alejandro Toledo's bid for office.

Mr Paniagua has repeatedly denied the accusations.

Fears revived

With Toledo, a centre-left economist, holding a commanding lead - but not a majority - the battle seems to be for second place and the chance to face Mr Toledo in a run-off.

Mr Mantilla spoke to the press after the video was released

Mr Garcia, who was president from 1985 to 1990, is considered a strong candidate for second place.

But the appearance of the latest video may revive fears about Mr Garcia's honesty, giving boosts to Lourdes Flores and Fernando Olivera, the other main candidates.

Mr Montesinos, meanwhile, remains a fugitive.

The power-broker behind the 10-year presidency of Alberto Fujimori, Mr Montesinos disappeared in October of last year. He is wanted on charges of arms smuggling, drug trafficking and human rights abuses.

A Peruvian lawmaker said earlier this week that he believed the US was protecting Mr Montesinos because of an alleged CIA connection, but produced no proof for his claim.

The US Embassy in Peru denied the allegation, saying that the US government was "co-operating fully in the Montesinos investigation".